Question: What occupational carcinogen containing hydrogen has the highest decomposition point ?
Paraphrase: Which hydrogen - containing occupational carcinogen has the highest point of decomposition?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q21074597 . ?ent wdt:P2107 ?obj . ?ent wdt:P527 wd:Q556 } ORDER BY DESC(?obj)LIMIT 5 
Answer: chromic acid, phenylhydrazine, chromic acid, dimethyl sulfate